Heat exchanger

ABSTRACT

In a heat exchanger of the present invention for exchanging heat between fluid flowing in a flow passage in a heat exchanger tube and fluid flowing outside of said heat exchanger tube, a solid bar-like insertion member or a hollow bar-like insertion member whose opposite ends are closed is provided in said flow passage in which a fluid having phase change flows in gas-liquid two phase state or liquid phase state, a cross section of said insertion member is formed into a substantially circle shape, a polygonal shape or a starlike shape, and a cross-sectional area of a flow passage in which said fluid flows is reduced as a mass flow rate quality of said fluid is reduced. With this construction, it is possible to restrain the pressure loss at the time of evaporation, and the evaporation ability can be enhanced or can be restrained from being deteriorated.

TECHNICAL FIELD

[0001] The present invention relates to a heat exchanger such as a heatexchanger having fins or a double tube heat exchanger mainly used in anair conditioner.

BACKGROUND TECHNIQUE

[0002] As shown in FIG. 8, a conventional heat exchanger having finscomprises fins 201 arranged at a predetermined distance from oneanother, and heat exchanger tubes 202 inserted through fin surfaces ofthe fins 201 perpendicularly to the latter. A current 203 of air flowsin the direction of the arrow between the fins, and exchanges heat withfluid flowing the passages of the heat exchanger tubes 202. When such aheat exchanger having fins is used, it is common that an end portionthereof is bent at a predetermined radius of curvature R, and the heatexchanger is accommodated in an outdoor unit of an air conditioner.

[0003] First prior art (Japanese Patent Application Laid-open No.S61-15089) is shown in FIGS. 9a and 9 b.

[0004]FIG. 9a is a vertical sectional view showing a portion of a heatexchanger tube, and FIG. 9b is an enlarged sectional view of anessential portion showing an inner wall surface of the heat exchangertube.

[0005] According to the first prior art of the heat exchanger, a coil204 comprising spirally wound metal fine wire is inserted into a heatexchanger tube 202, an outer periphery of this coil 204 is tightly fixedto an inner surface of the heat exchanger tube 202, and a large numberof powdery members 205 are jointed to the inner surface of the heatexchanger tube 202 to form a porous material layer.

[0006] According to this structure, heat transfer area of the innersurface of the heat exchanger tube 202 is increased, a turbulent floweffect, a capillary action effect and a nucleate boiling effect areexhibited to enhance the heat transfer performance.

[0007] Second prior art (Japanese Utility Model Registration ApplicationLaid-open No. S58-52491) is shown in FIG. 10.

[0008]FIG. 10 is a sectional view of a heat exchanger having fins takenalong the surface passing through the center of a heat exchanger tubethereof.

[0009] According to the second prior art, a spacer 206 which can bedeformed by heat is inserted into a heat exchanger tube 202, and afterthe insertion, the spacer 206 is heated so that the spacer 206 istightly adhered to an inner wall of the tube. A fin group 201 is jointedto an outer peripheral surface of the heat exchanger tube 202.

[0010] With this structure, the heat transfer area of the inner surfaceof the heat exchanger tube 202 is increased, and a turbulent flow effectis exhibited to enhance the heat transfer performance.

[0011] Third prior art (Japanese Patent Application No. H10-2638) isshown in FIG. 11.

[0012]FIG. 11 is a perspective view showing a structure of a heatexchanger having fins.

[0013] According to the third prior art, in the heat exchanger havingfins functioning as a condenser, the number of paths of an outlet tube207 for refrigerant is reduced, the outlet tube 207 is disposed in thewindward side with respect to the direction 203 of air flow, and a fin201 between the adjacent tubes 202 at the downwind side is provided witha slit 208 in the longitudinal direction of the fin 201.

[0014] With this structure, it is regarded that when the heat exchangeris used as a condenser, since it is possible to increase the speed inthe tube mainly by the outlet tube 207 which is excessively cooledregion, the heat transfer performance is enhanced, and by disposing theexcessively cooled region having low temperature in the windward side,it is possible to increase the temperature difference between the airand the excessively cooled region, and the condense performance can beenhanced.

[0015] Forth prior art (Japanese Patent Application No. S57-127732) isshown in FIG. 12.

[0016]FIG. 12 is a perspective view showing a structure of a heatexchanger having fins.

[0017] According to the fourth prior art, in the heat exchanger havingfins functioning as a condenser, the diameter of an outlet tube 209 ofrefrigerant is made thinner than those of other portions.

[0018] According to this structure, it is regarded that when the heatexchanger is used as a condenser, since it is possible to increase thespeed in the tube by the outlet tube 209 which is excessively cooledregion, the heat transfer performance is enhanced, and by disposing theexcessively cooled region having low temperature in the windward side,it is possible to increase the temperature difference between the airand the excessively cooled region, and the condense performance can beenhanced.

[0019] Fifth prior art (Japanese Patent Application No. H2-103355) isshown in FIGS. 13a and 13 b.

[0020]FIG. 13a is a perspective view showing a structure of a heatexchanger having fins, and FIG. 13b is a sectional view of a heatexchanger tube constituting the heat exchanger.

[0021] According to the fifth prior art, in the heat exchanger havingfins functioning as a condenser, inner rods 211 are inserted in the heatexchanger tube 210 in the vicinity of the refrigerant outlet.

[0022] With this structure, it is regarded that the heat exchangerhaving fins used as the condenser can reduce the amount of refrigerantcharged by the inner rods 211 inserted in the excessive cooled regions.

[0023] However, according to the structure of the first prior art, sincea wire of very small diameter is used as the coil, the volume of thetube can not be remarkably reduced by inserting the coil. Further, whenthe heat exchanger is used as a condenser, the inner surface of the tubewhich is the heat transfer surface is liable to be covered with a thickcondensed liquid film and there is a problem that the heat exchangingperformance is lowered.

[0024] According to the structure of the second prior art, since thisprior art mainly aims at increasing the heat transfer area of the innersurface of the heat transfer tube and at the turbulent flow effect, andthe thickness of the spacer is not specified, it is judged that thethickness of the spacer is equal to that of the heat exchanger tube, andthe volume of the tube can not be remarkably reduced by inserting thecoil. Further, when the heat exchanger is used as a condenser, the innersurface of the tube which is the heat transfer surface is liable to becovered with a thick condensed liquid film and there is a problem thatthe heat exchanging performance is lowered.

[0025] According to the structure of the third prior art, the currentspeed can be increased by minimizing the number of paths, but thecurrent speed of the minimum paths is the highest, and it is notpossible to further enhance the speed. Further, the speed can only bechanged at least for one heat exchanger tube by on heat exchanger tube.It is not possible to reduce the volume in the tube. Further, when theheat exchanger is used as a condenser, the inner surface of the tubewhich is the heat transfer surface is liable to be covered with a thickcondensed liquid film and there is a problem that the heat exchangingperformance is lowered.

[0026] According to the structure of the fourth prior art, the currentspeed in the thin tube can be increased, and the current speed can bearbitrarily determined by selecting the diameter of the thin tube, butin order to change the diameter of the thin tube, it is necessary tochange the molding dies of the fin having a hole in which the thin tubeis inserted. Therefore, it is necessary to make a significant investmentin the molding dies, and it is not easy to change the diameter. It isnot possible to reduce the volume in the tube. Further, when the heatexchanger is used as a condenser, the inner surface of the tube which isthe heat transfer surface is liable to be covered with a thick condensedliquid film and there is a problem that the heat exchanging performanceis lowered.

[0027] According to the structure of the fifth prior art, this is onlyeffective to reduce the amount of refrigerant when the heat exchanger isused as a condenser. When the heat exchanger is used as an evaporator,since it is described that a member which satisfies the pressure of 4kg/cm² is inserted to the outlet of the condenser, this will bring abouta remarkable increase in pressure loss, and there is a problem that theevaporation ability is remarkably lowered.

[0028] The present invention has been accomplished to solve the problemsof the prior art, and it is an object of the invention to enhance theevaporation ability or to restrain the evaporation ability from loweringwhile restraining the pressure loss at the time of evaporation byinserting, into a heat exchanger tube, a member which reduces therefrigerant flow passage as the mass flow rate quality (drynessfraction) is increased.

[0029] Further, when the heat exchanger is used as a condenser, it isanother object of the invention to provide a heat exchanger capable ofreducing the thickness of the liquid film of an inner surface of a tubeby adhering the condensed liquid to an outer surface of a memberinserted into two-phase region, reducing the cross-sectional area of theflow passage in the heat exchanger tube by the insertion member,enhancing the current flow of the refrigerant flowing in the heatexchanger tube, and enhancing the heat exchanging performance.

[0030] Furthermore, it is another object of the invention to provide aheat exchanger capable of reducing the amount of refrigerant to becharged by reducing the volume in the heat exchanger tube.

DISCLOSURE OF THE INVENTION

[0031] According to a first aspect, there is provided a heat exchangerfor exchanging heat between fluid flowing in a flow passage in a heatexchanger tube and fluid flowing outside of the heat exchanger tube,wherein a solid bar-like insertion member or a hollow bar-like insertionmember whose opposite ends are closed is provided in the flow passage inwhich a fluid having phase change flows in gas-liquid two phase state orliquid phase state, a cross section of the insertion member is formedinto a substantially circle shape, a polygonal shape or a starlikeshape, and a cross-sectional area of a flow passage in which the fluidflows is reduced as a mass flow rate quality of the fluid is reduced.

[0032] According to this construction, since the influence of thepressure loss is increased as the mass flow rate quality is increased,the pressure loss can effectively be reduced by widening the flowpassage having great mass flow rate quality, and the evaporation abilitycan be enhanced or restrained from lowering. When the heat exchanger isused as a condenser, if the current speed of the refrigerant flowing thein heat exchanger tube in a flow passage having small mass flow ratequality is increased, it is possible to reduce the thickness of theliquid film of the inner surface of the tube due to the condensedliquid, and it is possible to obtain a heat exchanger having high heatexchanging performance in the tube. Further, since the area of the outersurface of the insertion member is increased by forming the crosssection of the insertion member into polygonal shape or starlike shape,the amount of condensed liquid adhered to the insertion member isincreased, and it is possible to further reduce the thickness of thecondensed liquid film on the inner peripheral surface of the heatexchanger tube, and to enhance the heat transfer coefficient. Further,since the volume in the heat exchanger tube can be reduced, the amountof refrigerant to be charged can be reduced.

[0033] According to a second aspect, there is provided a heat exchangerfor exchanging heat between fluid flowing in a flow passage in a heatexchanger tube and fluid flowing outside of the heat exchanger tube,wherein a bar-like insertion member is provided in the flow passage inwhich a fluid having phase change flows in gas-liquid two phase state orliquid phase state, and a cross-sectional area of a flow passage inwhich the fluid flows is reduced as a mass flow rate quality of thefluid is reduced.

[0034] According to this construction, since the influence of thepressure loss is increased as the mass flow rate quality is increased,the pressure loss can effectively be reduced by widening the flowpassage having great mass flow rate quality, and the evaporation abilitycan be enhanced or restrained from lowering. When the heat exchanger isused as a condenser, if the current speed of the refrigerant flowing thein heat exchanger tube in a flow passage having small mass flow ratequality is increased, it is possible to reduce the thickness of theliquid film of the inner surface of the tube due to the condensedliquid, and it is possible to obtain a heat exchanger having high heatexchanging performance in the tube. Further, since the volume in theheat exchanger tube can be reduced, the amount of refrigerant to becharged can be reduced.

[0035] According to a third aspect, in the first or second aspect, across-sectional area of the insertion member is discontinuously varied.

[0036] According to this construction, it is possible to reduce thecross-sectional area of the flow passage in which the fluid flows can bereduced as the mass flow rate quality of the fluid is reduced by varyingthe cross-sectional area of the insertion member. Further, it ispossible to easily change the cross-sectional area of the flow passageby combining insertion members having different diameters.

[0037] According to a fourth aspect, in the first or second aspect, across-sectional area of the insertion member is continuously varied.

[0038] According to this construction, it is possible to reduce thecross-sectional area of the flow passage in which the fluid flows can bereduced as the mass flow rate quality of the fluid is reduced by varyingthe cross-sectional area of the insertion member. Further, it ispossible to optimally reduce the pressure loss and to exploit the fullheat exchanging performance by continuously changing the cross-sectionalarea of the insertion member.

[0039] According to a fifth aspect, there is provided a heat exchangerfor exchanging heat between fluid flowing in a flow passage in a heatexchanger tube and fluid flowing outside of the heat exchanger tube,wherein a solid bar-like insertion member or a hollow bar- likeinsertion member whose opposite ends are closed is provided in the flowpassage in which a fluid having phase change flows in gas-liquid twophase state or liquid phase state, and a cross section of the insertionmember is formed into a substantially circle shape, a polygonal shape ora starlike shape.

[0040] According to this construction, when the heat exchanger is usedas a condenser, the thickness of the liquid film of the inner surface ofthe tube by the condensed liquid in the two-phase region or liquid phasecan be reduced, and the current speed of the refrigerant flowing in theheat exchanger tube can be enhanced so that a heat exchanger having highheat exchanging performance in the tube can be obtained. Further, sincethe area of the outer surface of the insertion member is increased byforming the cross section of the insertion member into polygonal shapeor starlike shape, the amount of condensed liquid adhered to theinsertion member is increased, and it is possible to further reduce thethickness of the condensed liquid film on the inner peripheral surfaceof the heat exchanger tube, and to enhance the heat transfercoefficient. Further, since the volume in the heat exchanger tube can bereduced, the amount of refrigerant to be charged can be reduced.

[0041] According to a sixth aspect, in any one of the first, second andfifth aspects, the insertion member is provided on its outer surfacewith a groove, or a bump and a dip.

[0042] According to this construction, since the area of the outersurface of the insertion member is increased, the amount of condensedliquid adhered to the insertion member is increased, and it is possibleto further reduce the thickness of the condensed liquid film on theinner peripheral surface of the heat exchanger tube, and to enhance theheat transfer coefficient.

[0043] According to a seventh aspect, in any one of the first, secondand fifth aspects, the insertion member is made of porous material.

[0044] According to this construction, since the area of the outersurface of the insertion member is increased by the porous material, theamount of condensed liquid adhered to the insertion member is increased,and it is possible to further reduce the thickness of the condensedliquid film on the inner peripheral surface of the heat exchanger tube,and to enhance the heat transfer coefficient.

[0045] According to an eighth aspect, in any one of the first, secondand fifth aspects, the insertion member is provided in plural intobundle.

[0046] According to this construction, since the plurality of insertionmembers are provided, the area of the outer surfaces of the insertionmembers is increased, the amount of condensed liquid adhered to theinsertion member is increased, and it is possible to further reduce thethickness of the condensed liquid film on the inner peripheral surfaceof the heat exchanger tube, and to enhance the heat transfercoefficient.

[0047] According to a ninth aspect, in any one of the first, second andfifth aspects, a refrigerant comprising hydro fluorocarbon (HFC) orhydrocarbon (HC) as main component is used as the fluid flowing in theflow passage in the heat exchanger tube.

[0048] According to this construction, the refrigerant comprising hydrofluorocarbon (HFC) or hydrocarbon (HC) as main component has higherrefrigerant density at the same cycle point than conventional R22 andthus has lower current speed, and the pressure loss is lowered to about70% when the refrigerant has the same ability as the conventional R22.For this reason, the heat transfer coefficient is enhanced and the heatexchanging coefficient is also enhanced especially by using R410A,propane (R290) or the like as refrigerant. Further, if the hydrofluorocarbon (HFC) or hydrocarbon (HC) is used, the value of the ozonedestroy potential (ODP) is 0. Although the value of the global warmingpotential (GWP) of the hydro fluorocarbon (HFC) is high, the globalwarming potential (GWP) of the hydrocarbon (HC) is extremely closer to0. Therefore, the environmental problem can be overcome.

[0049] According to a tenth aspect, in the third aspect, the insertionmember is provided on its outer surface with a groove, or a bump and adip.

[0050] According to this construction, since the area of the outersurface of the insertion member is increased, the amount of condensedliquid adhered to the insertion member is increased, and it is possibleto further reduce the thickness of the condensed liquid film on theinner peripheral surface of the heat exchanger tube, and to enhance theheat transfer coefficient.

[0051] According to a eleventh aspect, in the third aspect, theinsertion member is made of porous material.

[0052] According to this construction, since the area of the outersurface of the insertion member is increased by the porous material, theamount of condensed liquid adhered to the insertion member is increased,and it is possible to further reduce the thickness of the condensedliquid film on the inner peripheral surface of the heat exchanger tube,and to enhance the heat transfer coefficient.

[0053] According to an twelfth aspect, in the third aspect, theinsertion member is provided in plural into bundle.

[0054] According to this construction, since the plurality of insertionmembers are provided, the area of the outer surfaces of the insertionmembers is increased, the amount of condensed liquid adhered to theinsertion member is increased, and it is possible to further reduce thethickness of the condensed liquid film on the inner peripheral surfaceof the heat exchanger tube, and to enhance the heat transfercoefficient.

[0055] According to a thirteenth aspect, in the third aspect, arefrigerant comprising hydro fluorocarbon (HFC) or hydrocarbon (HC) asmain component is used as the fluid flowing in the flow passage in theheat exchanger tube.

[0056] According to this construction, the refrigerant comprising hydrofluorocarbon (HFC) or hydrocarbon (HC) as main component has higherrefrigerant density at the same cycle point than conventional R22 andthus has lower current speed, and the pressure loss is lowered to about70% when the refrigerant has the same ability as the conventional R22.For this reason, the heat transfer coefficient is enhanced and the heatexchanging coefficient is also enhanced especially by using R410A,propane (R290) or the like as refrigerant. Further, if the hydrofluorocarbon (HFC) or hydrocarbon (HC) is used, the value of the ozonedestroy potential (ODP) is 0. Although the value of the global warmingpotential (GWP) of the hydro fluorocarbon (HFC) is high, the globalwarming potential (GWP) of the hydrocarbon (HC) is extremely closer to0. Therefore, the environmental problem can be overcome.

[0057] According to a fourteenth aspect, in the fourth aspect, theinsertion member is provided on its outer surface with a groove, or abump and a dip.

[0058] According to this construction, since the area of the outersurface of the insertion member is increased, the amount of condensedliquid adhered to the insertion member is increased, and it is possibleto further reduce the thickness of the condensed liquid film on theinner peripheral surface of the heat exchanger tube, and to enhance theheat transfer coefficient.

[0059] According to a fifteenth aspect, in the fourth aspect, theinsertion member is made of porous material.

[0060] According to this construction, since the area of the outersurface of the insertion member is increased by the porous material, theamount of condensed liquid adhered to the insertion member is increased,and it is possible to further reduce the thickness of the condensedliquid film on the inner peripheral surface of the heat exchanger tube,and to enhance the heat transfer coefficient.

[0061] According to an sixteenth aspect, in the fourth aspect, theinsertion member is provided in plural into bundle.

[0062] According to this construction, since the plurality of insertionmembers are provided, the area of the outer surfaces of the insertionmembers is increased, the amount of condensed liquid adhered to theinsertion member is increased, and it is possible to further reduce thethickness of the condensed liquid film on the inner peripheral surfaceof the heat exchanger tube, and to enhance the heat transfercoefficient.

[0063] According to a seventeenth aspect, in the fourth aspect, arefrigerant comprising hydro fluorocarbon (HFC) or hydrocarbon (HC) asmain component is used as the fluid flowing in the flow passage in theheat exchanger tube.

[0064] According to this construction, the refrigerant comprising hydrofluorocarbon (HFC) or hydrocarbon (HC) as main component has higherrefrigerant density at the same cycle point than conventional R22 andthus has lower current speed, and the pressure loss is lowered to about70% when the refrigerant has the same ability as the conventional R22.For this reason, the heat transfer coefficient is enhanced and the heatexchanging coefficient is also enhanced especially by using R410A,propane (R290) or the like as refrigerant. Further, if the hydrofluorocarbon (HFC) or hydrocarbon (HC) is used, the value of the ozonedestroy potential (ODP) is 0. Although the value of the global warmingpotential (GWP) of the hydro fluorocarbon (HFC) is high, the globalwarming potential (GWP) of the hydrocarbon (HC) is extremely closer to0. Therefore, the environmental problem can be overcome.

BRIEF DESCRIPTION OF DRAWINGS

[0065]FIG. 1a is a sectional view of a heat exchanger having finsaccording to an embodiment of the present invention taken along thecenter line of a heat exchanger tube;

[0066]FIG. 1b is a sectional view taken along the line A-A in FIG. 1a;

[0067]FIG. 2a is a sectional view of a heat exchanger having finsaccording to another embodiment of the invention taken along the centerline of a heat exchanger tube;

[0068]FIG. 2b is a sectional view taken along the line A-A in FIG. 2a;

[0069]FIG. 3a is a sectional view of a heat exchanger having finsaccording to another embodiment of the invention taken along the centerline of a heat exchanger tube;

[0070]FIG. 3b is a sectional view taken along the line A-A in FIG. 3a;

[0071]FIG. 4a is a sectional view of a heat exchanger having finsaccording to another embodiment of the invention taken along the centerline of a heat exchanger tube;

[0072]FIG. 4b is a sectional view taken along the line A-A in FIG. 4a;

[0073]FIG. 5a is a sectional view of a heat exchanger having finsaccording to another embodiment of the invention taken along the centerline of a heat exchanger tube;

[0074]FIG. 5b is a sectional view taken along the line A-A in FIG. 5a;

[0075]FIG. 6a is a sectional view of a heat exchanger having finsaccording to another embodiment of the invention taken along the centerline of a heat exchanger tube;

[0076]FIG. 6b is a sectional view taken along the line A-A in FIG. 6a;

[0077]FIG. 7a is a sectional view of a heat exchanger having finsaccording to another embodiment of the invention taken along the centerline of a heat exchanger tube;

[0078]FIG. 7b is a sectional view taken along the line A-A in FIG. 7a;

[0079]FIG. 8 is a perspective view of the heat exchanger having fins;

[0080]FIG. 9a is a vertical sectional view showing a portion of a heatexchanger tube according to a first prior art;

[0081]FIG. 9b is an enlarged sectional view of an essential portionshowing an inner wall surface of the heat exchanger tube;

[0082]FIG. 10 is a sectional view of a heat exchanger having finsaccording to a second prior art taken along the surface passing throughthe center line of a heat exchanger tube;

[0083]FIG. 11 is a perspective view showing a construction of a heatexchanger having fins according to a third prior art;

[0084]FIG. 12 is a perspective view showing a construction of a heatexchanger having fins according to a fourth prior art;

[0085]FIG. 13a is a perspective view showing a construction of a heatexchanger having fins according to a fifth prior art;

[0086]FIG. 13b is a sectional view of a heat exchanger tube constitutingthe heat exchanger; and

[0087]FIG. 14 is an image view in which operation points ofrefrigerating cycle are added to Mollier chart.

BEST MODE FOR CARRYING OUT THE INVENTION

[0088] Embodiments of the present invention will be explained withreference to the drawings. Although heat exchangers having fins will beexplained in the following description of the embodiments, effect of thepresent invention is obtained in a flow passage in which refrigeranthaving phase change characteristics flows, and the same effect can beobtained even in inside or outside of inner tube of a heat exchangercomprising only a heat exchanger tube such as double tube heat exchangerif the fluid has phase change characteristic flows.

First Embodiment

[0089]FIG. 1a is a sectional view of a heat exchanger having fins takenalong the center line of a heat exchanger tube and FIG. 1b is asectional view taken along the line A-A in FIG. 1a. FIG. 14 is an imageview in which operation points of refrigerating cycle are added toMollier chart.

[0090] In FIGS. 1a and 1 b, the reference number 11 represents fins, 12represents a heat exchanger tube, 13A represents an insertion memberhaving constant cross-sectional area, and 13B represents an insertionmember having cross-sectional area which is changed continuouslydepending on position of a flow passage. The heat exchanger tube 12comprises three tubes 12A, 12B and 12C formed into U-shape, a U-benttube 12D connecting one ends of the tube 12A and the tube 12B, and aU-bent tube 12E connecting the other end of the tube 12B and one end ofthe tube 12C. Although the heat exchanger tube 12 comprises three tubes12A, 12B and 12C in this embodiment, the number of tubes maybe changedin accordance with ability of the heat exchanger. An insertion member13A is provided in a flow passage 14A at the side of a heat exchangertube end C of the tube 12A, and an insertion member 13B is provided in aflow passage 14B at the side of the U-bent tube 12D. The insertionmember 13B is disposed such that its end having small cross-sectionalarea is located at the opening side of the tube 12A.

[0091] When this heat exchanger having fins is used as a condenser, aheat exchanger end B is an inlet of fluid flowing in the flow passage,and a heat exchanger tube end C is an outlet of fluid flowing in theflow passage. When the heat exchanger having fins is used as thecondenser, gaseous fluid flows in from the heat exchanger tube end B,and liquid fluid flows out from the heat exchanger tube end C.Therefore, as the fluid flows from the heat exchanger tube end B to theheat exchanger tube end C, the mass flow rate quality of the fluidbecomes smaller. The arrow indicated the direction of fluid flowing inthe flow passage.

[0092] In FIG. 14, a line 212 indicates a saturated liquid line, a line213 indicates a saturated gas line, a solid line 225 indicates anoperation line when the insertion member is inserted, a broken line 226indicates an operation line at the time of normal time when the memberis not inserted, a point 214 indicates a suction point of a compressor,a point 215 indicates an inlet point of a condenser, a point 217indicates an outlet point of the condenser at the time of normal timewhen the member is not inserted, a point 219 indicates an inlet point ofan evaporator when the member is inserted, a point 220 indicates aninlet point of the evaporator at the time of normal time when the memberis not inserted, a point 222 indicates an outlet point of theevaporator, a point 216 indicates an average condensation temperature, apoint 221 indicates an average evaporation temperature, an area 223indicates an area in the vicinity of the condenser outlet, and an area224 indicates an area in the vicinity of the evaporator inlet.

[0093] When the heat exchanger is used as a condenser, in FIG. 1a, fluidflowing in the heat exchanger tube flows in from the side of the heatexchanger end B and flows out toward the heat exchanger end C. Duringthat time, the heat exchange is carried out between the fluid and aircurrent flowing in the gap between the fins provided around the outerperiphery of the heat exchanger tube 12. The flow passage 14B isgradually narrowed by the insertion member 13B, and the flow passage 14Ais narrowed by the insertion member 13A. Therefore, the speed the fluidflowing in the tube 12A gradually becomes faster in the flow passage 14Band the fluid flows in the flow passage 14A at the highest speed andthus, the heat transfer coefficient in the tube is enhanced.

[0094] In the present embodiment, since the insertion members 13A and13B are inserted in the vicinity 223 of the condenser outlet, thepressure loss is increased only in the vicinity of the condenser outlet223 as shown in FIG. 14, and the average condensation temperature 216 isrestrained from being lowered. In a gas-liquid two-phase region, sincethe condensed liquid is also adhered to the outer peripheral surfaces ofthe insertion members 13A and 13B, the thickness of the condensed liquidfilm of the inner peripheral surface of the tube 12A can be reduced, andthe heat transfer coefficient in the tube can be enhanced. Further, byproviding the insertion members 13A and 13B, the volume in the tube 12Acan be reduced, and the amount of refrigerant to be charged can bereduced.

[0095] When the heat exchanger is used as the evaporator, in FIG. 1a,the fluid flowing in the heat exchanger tube flows in the oppositedirection from that when the heat exchanger is used as the condenser,the fluid flowing in the heat exchanger tube flows in from the side ofthe heat exchanger end C and flows out toward the heat exchanger end B.During that time, the heat exchange is carried out between the fluid andair current flowing in the gap between the fins provided around theouter periphery of the heat exchanger tube 12. The flow passage 14A isgradually narrowed by the insertion member 13A, and the flow passage 14Bis gradually narrowed by the insertion member 13B. Therefore, the speedthe fluid flowing in the tube 12A becomes faster and thus, the heattransfer coefficient in the tube is enhanced.

[0096] In the present embodiment, since the insertion members 13A and13B are inserted in the vicinity 224 of the evaporator, as shown withthe solid line 225 in FIG. 14, the pressure loss is increased in thevicinity 224 of the evaporator inlet, and as the mass flow rate qualityis increased, the cross-sectional area of the flow passage is increasedand thus, the pressure loss is reduced. Therefore, even if the pressureloss is increased, the pressure loss is increased only in the vicinity224 of the evaporator, the heat transfer coefficient is enhanced due tothe increase in flowing speed of the fluid, and the evaporation abilitycan be enhanced. Therefore, it is possible to restrain at least theevaporation ability from being lowered.

[0097] It is preferable that the shape of the cross section of each ofthe insertion members 13A and 13B is polygonal shape or starlike shape,in addition to substantially circular shape. Each of the insertionmembers 13A and 13B comprises a solid bar-member or a hollow bar-likemember whose opposite ends are closed. The material of the each of theinsertion members 13A and 13B is metal such as iron or aluminum or resinhaving corrosion resistance with respect to the refrigerant.

Second Embodiment

[0098]FIG. 2a is a sectional view of a heat exchanger having finsaccording to another embodiment of the invention taken along the centerline of a heat exchanger tube, and FIG. 2b is a sectional view takenalong the line A-A in FIG. 2a. The same members as those in the aboveembodiment are designated with the same reference numbers, and detailedexplanation thereof will be omitted.

[0099] In the second embodiment, as shown in FIGS. 2a and 2 b, insertionmembers 23A, 23B and 23C are provided in the flow passage 14A of thetube 12A. Here, the cross-sectional area of each of the insertionmembers 23A, 23B and 23C is constant, the cross-sectional area of theinsertion member 23A is greater than that of the insertion member 23B,and the cross-sectional area of the insertion member 23B is greater thanthat of the insertion member 23C. The insertion members 23A, 23B and 23Care connected in this order. The insertion member 23A having thegreatest cross-sectional area is disposed at the side of the heatexchanger tube end C.

[0100] Since the insertion members comprise the insertion members 23A,23B and 23C, and the insertion ember 23A is disposed at the side of theheat exchanger tube end C in this manner, the flow passage 14 in whichthe fluid can flow is gradually narrowed as the mass flow rate qualitybecomes smaller, the current speed of the fluid flowing in the flowpassage 14 is enhanced, and the heat transfer coefficient in the tube isenhanced.

[0101] When the heat exchanger is used as the condenser, in the presentembodiment also, since the insertion members 23A, 23B and 23C areinserted in the vicinity 223 of the condenser outlet, the pressure lossis increased only in the vicinity of the condenser outlet 223, and theaverage condensation temperature 216 is restrained from being lowered.In a gas-liquid two-phase region, since the condensed liquid is alsoadhered to the outer peripheral surfaces of the insertion members 23A,23B and 23C, the thickness of the condensed liquid film of the innerperipheral surface of the tube 12A can be reduced, and the heat transfercoefficient in the tube can be enhanced. Further, by providing theinsertion members 23A, 23B and 23C, the volume in the tube 12A can bereduced, and the amount of refrigerant to be charged can be reduced.

[0102] When the heat exchanger is used as the evaporator, in the presentembodiment also, since the insertion members 23A, 23B and 23C areinserted in the vicinity 224 of the evaporator, as shown with the solidline 225 in FIG. 14, the pressure loss is increased in the vicinity 224of the evaporator inlet, and as the mass flow rate quality is increased,the cross-sectional area of the flow passage is increased and thus, thepressure loss is reduced. Therefore, even if the pressure loss isincreased, the pressure loss is increased only in the vicinity 224 ofthe evaporator, the heat transfer coefficient is enhanced due to theincrease in flowing speed of the fluid, and the evaporation ability canbe enhanced. Therefore, it is possible to restrain at least theevaporation ability from being lowered.

[0103] Further, as in the present embodiment, it is possible to easilyvary the cross-sectional area of the flow passage by combining insertionmembers having different diameters.

[0104] Although the description has been made in the present embodimentwhile taking, as an example, the case in which only the flow passage 14Ais provided with the insertion members, the flow passage 14B may beprovided with the insertion member 24B, and the tube 12B may be providedat its lower flow passage with the insertion member 24C, and insertionmembers having different cross-sectional areas may be provided in steps(in front and behind the bent portion of the heat exchanger tubes) ofthe tubes.

Third Embodiment

[0105]FIG. 3a is a sectional view of a heat exchanger having finsaccording to another embodiment of the invention taken along the centerline of a heat exchanger tube, and FIG. 3b is a sectional view takenalong the line A-A in FIG. 3a. The same members as those in the aboveembodiment are designated with the same reference numbers, and detailedexplanation thereof will be omitted.

[0106] In the third embodiment, as shown in FIGS. 3a and 3 b, aninsertion member 33 whose cross-sectional area is continuously varied isprovided in the flow passage 14A of the tube 12A. The insertion member33 is disposed such that its end having greater cross-sectional area islocated at the side of the heat exchanger tube end C.

[0107] Since the insertion member comprises the insertion member 33whose cross-sectional area is continuously varied, and the insertionmember 33 is disposed such that its end having greater cross-sectionalarea is located at the side of the heat exchanger tube end C in thismanner, the flow passage 14 in which the fluid can flow is graduallynarrowed as the mass flow rate quality becomes smaller, the currentspeed of the fluid flowing in the flow passage 14 is enhanced, and theheat transfer coefficient in the tube is enhanced.

[0108] When the heat exchanger is used as the condenser, in the presentembodiment also, since the insertion member 33 is inserted in thevicinity 223 of the condenser outlet, the pressure loss is increasedonly in the vicinity of the condenser outlet 223, and the averagecondensation temperature 216 is restrained from being lowered. In agas-liquid two-phase region, since the condensed liquid is also adheredto the outer peripheral surface of the insertion member 33, thethickness of the condensed liquid film of the inner peripheral surfaceof the tube 12A can be reduced, and the heat transfer coefficient in thetube can be enhanced. Further, by providing the insertion member 33, thevolume in the tube 12A can be reduced, and the amount of refrigerant tobe charged can be reduced.

[0109] Further, it is possible to optimally reduce the pressure loss andto exploit the full heat exchanging performance by continuously changingthe cross-sectional area of the insertion member.

[0110] When the heat exchanger is used as the evaporator, in the presentembodiment also, since the insertion member 33 is inserted in thevicinity 224 of the evaporator, as shown with the solid line 225 in FIG.14, the pressure loss is increased in the vicinity 224 of the evaporatorinlet, and as the mass flow rate quality is increased, thecross-sectional area of the flow passage is increased and thus, thepressure loss is reduced. Therefore, even if the pressure loss isincreased, the pressure loss is increased only in the vicinity 224 ofthe evaporator, the heat transfer coefficient is enhanced due to theincrease in flowing speed of the fluid, and the evaporation ability canbe enhanced. Therefore, it is possible to restrain at least theevaporation ability from being lowered.

[0111] Although the description has been made in the present embodimentwhile taking, as an example, the case in which only the flow passage 14Ais provided with the insertion member, the flow passage 14B may also beprovided with an insertion member, and the tube 12B may also be providedat its lower flow passage with an insertion member. When the insertionmembers are provided in a plurality of tubes, it is preferable that thecross-sectional area of each of the insertion members is continuouslyvaried.

Fourth Embodiment

[0112]FIG. 4a is a sectional view of a heat exchanger having finsaccording to another embodiment of the invention taken along the centerline of a heat exchanger tube, and FIG. 4b is a sectional view takenalong the line A-A in FIG. 4a. The same members as those in the aboveembodiment are designated with the same reference numbers, and detailedexplanation thereof will be omitted.

[0113] As shown in FIGS. 4a and 4 b, insertion members 43 each having aconstant cross-sectional area are provided in flow passages 14A and 14Bof the tube 12A as well as in flow passages 14C and 14D of the tube 12B.No insertion members is provided in each of the flow passages 14E and14F of the tube 12C.

[0114] Since the flow passages 14A, 14B, 14C and 14D having small massflow rate qualities are narrower than the flow passages 14E and 14Fhaving great mass flow rate qualities, the current speed of the fluidflowing in the flow passages 14A, 14B, 14C and 14D is enhanced, and theheat transfer coefficient in the tube is enhanced.

[0115] When the heat exchanger is used as the condenser, in the presentembodiment also, since the insertion member 43 is inserted at the sideof the condenser outlet, the average condensation temperature 216 isrestrained from being lowered. In a gas-liquid two-phase region, sincethe condensed liquid is also adhered to the outer peripheral surface ofthe insertion member 43, the thickness of the condensed liquid film ofthe inner peripheral surfaces of the tubes 12A and 12B can be reduced,and the heat transfer coefficient in the tube can be enhanced. Further,by providing the insertion member 43, the volume in each of the tubes12A and 12B can be reduced, and the amount of refrigerant to be chargedcan be reduced.

[0116] When the heat exchanger is used as the evaporator, in the presentembodiment also, since the insertion member 43 is inserted at the sideof the evaporator inlet, the pressure loss is great at the side of theevaporator inlet, and in a place where the mass flow rate quality isgreat, the cross-sectional area of the flow passage is great and thus,the pressure loss is reduced. Therefore, even if the pressure loss isincreased, the pressure loss is increased only at the side of theevaporator inlet, the heat transfer coefficient is enhanced due to theincrease in flowing speed of the fluid, and the evaporation ability canbe enhanced. Therefore, it is possible to restrain at least theevaporation ability from being lowered.

[0117] Further, by using the insertion members 43 each having theconstant cross-sectional area, since a large number of the same members,it is possible to reduce the costs of the insertion members to theminimum.

Fifth Embodiment

[0118]FIG. 5a is a sectional view of a heat exchanger having finsaccording to another embodiment of the invention taken along the centerline of a heat exchanger tube, and FIG. 5b is a sectional view takenalong the line A-A in FIG. 5a. The same members as those in the aboveembodiment are designated with the same reference numbers, and detailedexplanation thereof will be omitted.

[0119] As shown in FIGS. 5a and 5 b, in a flow passage 14A of the tube12A, an insertion member 53 whose cross-sectional area is continuouslyvaried and formed with a plurality of grooves 53A in a longitudinaldirection of an outer surface thereof is provided. The insertion member53 is disposed such that its one end having greater cross-sectional areais located at the side of the heat exchanger tube end C.

[0120] Since the insertion member comprises the insertion member 53whose cross-sectional area is continuously varied, and the insertionmember 33 is disposed such that its end having greater cross-sectionalarea is located at the side of the heat exchanger tube end C in thismanner, the flow passage 14 in which the fluid can flow is graduallynarrowed as the mass flow rate quality becomes smaller, the currentspeed of the fluid flowing in the flow passage 14 is enhanced, and theheat transfer coefficient in the tube is enhanced.

[0121] When the heat exchanger is used as the condenser, in the presentembodiment also, since the insertion member 53 is inserted in thevicinity 223 of the condenser outlet, the pressure loss is increasedonly in the vicinity of the condenser outlet 223, and the averagecondensation temperature 216 is restrained from being lowered. Thecondensed liquid is adhered to the outer peripheral surface of theinsertion member 53, but since the amount of the condensed liquidadhered to the insertion member 53 is increased because the outer areaof the insertion member 53 is increased due to the grooves 53A, thethickness of the condensed liquid film of the inner peripheral surfaceof the tube 12A can further be reduced, and the heat transfercoefficient in the tube is enhanced. Further, the volume in the heatexchanger tube can be reduced by the insertion member, and the amount ofrefrigerant to be charged can be reduced.

[0122] Further, since the diameter of the insertion member iscontinuously varied, it is possible to optimally reduce the pressure andto exploit the full ability.

[0123] When the heat exchanger is used as the evaporator, in the presentembodiment also, since the insertion member 53 is inserted in thevicinity 224 of the evaporator, as shown with the solid line 225 in FIG.14, the pressure loss is increased in the vicinity 224 of the evaporatorinlet, and as the mass flow rate quality is increased, thecross-sectional area of the flow passage is increased and thus, thepressure loss is reduced. Therefore, even if the pressure loss isincreased, the pressure loss is increased only in the vicinity 224 ofthe evaporator, the heat transfer coefficient is enhanced due to theincrease in flowing speed of the fluid, and the evaporation ability canbe enhanced. Therefore, it is possible to restrain at least theevaporation ability from being lowered.

[0124] Although FIG. 5a shows straight grooves, if helical grooves areprovided, turbulent flow is promoted, which enhances the heat transfercoefficient and thus, the ability is enhanced.

[0125] Further, the cross-sectional area of the insertion member 53 maybe varied in front and behind the bent portion of the heat exchangertube. The same effect can be obtained even if the groove is formed withbumps and dips by dimple processing.

Sixth Embodiment

[0126]FIG. 6a is a sectional view of a heat exchanger having finsaccording to another embodiment of the invention taken along the centerline of a heat exchanger tube, and FIG. 6b is a sectional view takenalong the line A-A in FIG. 6a. The same members as those in the aboveembodiment are designated with the same reference numbers, and detailedexplanation thereof will be omitted.

[0127] In the sixth embodiment, as shown in FIGS. 6a and 6 b, aninsertion member 63 made of porous material and whose cross-sectionalarea is continuously varied is provided in the flow passage 14A of thetube 12A. The insertion member 63 is disposed such that its one endhaving greater cross-sectional area is located at the side of the heatexchanger tube end C.

[0128] Since the insertion member comprises the insertion member 63whose cross-sectional area is continuously varied, and the insertionmember 63 is disposed such that its end having greater cross-sectionalarea is located at the side of the heat exchanger tube end C in thismanner, the flow passage 14A in which the fluid can flow is graduallynarrowed as the mass flow rate quality becomes smaller, the currentspeed of the fluid flowing in the flow passage 14A is enhanced, and theheat transfer coefficient in the tube is enhanced.

[0129] When the heat exchanger is used as the condenser, in the presentembodiment also, since the insertion member 63 is inserted in thevicinity 223 of the condenser outlet, the pressure loss is increasedonly in the vicinity of the condenser outlet 223, and the averagecondensation temperature 216 is restrained from being lowered. Thecondensed liquid is adhered to the outer peripheral surface of theinsertion member 63, but since the insertion member 63 is formed intoporous shape, the outer area of the insertion member 63 can beincreased, the thickness of the condensed liquid film of the innerperipheral surface of the tube 12A can further be reduced, and the heattransfer coefficient in the tube is enhanced. Further, the volume in theheat exchanger tube can be reduced by the insertion member, and theamount of refrigerant to be charged can be reduced.

[0130] Further, since the diameter of the insertion member 63 iscontinuously varied, it is possible to optimally reduce the pressure andto exploit the full ability.

[0131] When the heat exchanger is used as the evaporator, in the presentembodiment also, since the insertion member 63 is inserted in thevicinity 224 of the evaporator, as shown with the solid line 225 in FIG.14, the pressure loss is increased in the vicinity 224 of the evaporatorinlet, and as the mass flow rate quality is increased, thecross-sectional area of the flow passage is increased and thus, thepressure loss is reduced. Therefore, even if the pressure loss isincreased, the pressure loss is increased only in the vicinity 224 ofthe evaporator, the heat transfer coefficient is enhanced due to theincrease in flowing speed of the fluid, and the evaporation ability canbe enhanced. Therefore, it is possible to restrain at least theevaporation ability from being lowered.

[0132] Although FIG. 6a shows the member formed by hardening fineparticles, the same effect can be obtained even if the porous member isformed by adhering the particles onto a smooth outer surface in view ofstrength. Further, even if particles having different particle diameterare mixed, the same effect can be obtained. The cross-sectional area ofthe insertion member 63 may be varied in front of and behind the bentportion of the heat exchanger tube.

Seventh Embodiment

[0133]FIG. 7a is a sectional view of a heat exchanger having finsaccording to another embodiment of the invention taken along the centerline of a heat exchanger tube, and FIG. 7b is a sectional view takenalong the line A-A in FIG. 7a. The same members as those in the aboveembodiment are designated with the same reference numbers, and detailedexplanation thereof will be omitted.

[0134] According to the present embodiment, as shown in FIGS. 7a and 7b, a plurality of insertion members 73A, 73B and 73C are tied in abundle and provided in the flow passage 14A of the tube 12A. Thecross-sectional area of each of the insertion members 73 is continuouslyvaried. The insertion member 73 is disposed such that its one end havinggreater cross-sectional area is located at the side of the heatexchanger tube end C.

[0135] Since the insertion member comprises the insertion member 73whose cross-sectional area is continuously varied, and the insertionmember 73 is disposed such that its end having greater cross-sectionalarea is located at the side of the heat exchanger tube end C in thismanner, the flow passage 14A in which the fluid can flow is graduallynarrowed as the mass flow rate quality becomes smaller, the currentspeed of the fluid flowing in the flow passage 14A is enhanced, and theheat transfer coefficient in the tube is enhanced.

[0136] When the heat exchanger is used as the condenser, in the presentembodiment also, since the insertion member 73 is inserted in thevicinity 223 of the condenser outlet, the pressure loss is increasedonly in the vicinity of the condenser outlet 223, and the averagecondensation temperature 216 is restrained from being lowered. Thecondensed liquid is adhered to the outer peripheral surface of theinsertion member 73, but since the plurality of insertion members 73A,73B and 73C are tied into bundle, the outer area of the insertion member73 can be increased, the thickness of the condensed liquid film of theinner peripheral surface of the tube 12A can further be reduced, and theheat transfer coefficient in the tube is enhanced. Further, the volumein the heat exchanger tube can be reduced by the insertion member, andthe amount of refrigerant to be charged can be reduced.

[0137] Further, since the diameter of the insertion member 73 iscontinuously varied, it is possible to optimally reduce the pressure andto exploit the full ability.

[0138] When the heat exchanger is used as the evaporator, in the presentembodiment also, since the insertion member 73 is inserted in thevicinity 224 of the evaporator, as shown with the solid line 225 in FIG.14, the pressure loss is increased in the vicinity 224 of the evaporatorinlet, and as the mass flow rate quality is increased, thecross-sectional area of the flow passage is increased and thus, thepressure loss is reduced. Therefore, even if the pressure loss isincreased, the pressure loss is increased only in the vicinity 224 ofthe evaporator, the heat transfer coefficient is enhanced due to theincrease in flowing speed of the fluid, and the evaporation ability canbe enhanced. Therefore, it is possible to restrain at least theevaporation ability from being lowered.

[0139] Further, as shown in FIG. 8, when the heat exchanger tube is bentto form a heat exchanger, it is possible to restrain the deformation ofthe member at the bent portion and thus, the processing is easy.

[0140] Although FIG. 7a shows straight bars, if helically twisted barsare combined, turbulent flow is promoted, which enhances the heattransfer coefficient and thus, the ability is enhanced.

[0141] Although the fluid is not specifically described in the aboveembodiments, the following refrigerant can be used.

[0142] Although a single refrigerant (R22) is conventionally used as arefrigerant used for an air conditioner, single refrigerant orazeotropic refrigerant having small temperature gradient of airtemperature in a refrigeration cycle, such as R32/R125 (50/50 wt %)(which will be referred to as R410A hereinafter) in hydro fluorocarbon(HFC), or propane (R290) in hydrocarbon (HC) may be used as asubstitutable refrigerant. Each of these refrigerants has greaterrefrigerant density at the same cycle point as compared with theconventional R22 in the refrigeration cycle and thus, has characteristicthat the current speed is reduced.

[0143] That is, when the same ability is required, the pressure loss ofthe R410 in a heat exchanger or a tube is about 70% of that of the R22.

[0144] For this reason, if refrigerant such as R410A, propane (R290) orthe like is used, the heat transfer coefficient is enhanced, and theefficient of the heat exchanger is enhanced. Further, if the hydrofluorocarbon (HFC) or hydrocarbon (HC) is used, the value of the ozonedestroy potential (ODP) is 0. Although the value of the global warmingpotential (GWP) of the hydro fluorocarbon (HFC) is high, the globalwarming potential (GWP) of the hydrocarbon (HC) is extremely closer to0. Therefore, the environmental problem can be overcome.

What is claimed is:
 1. A heat exchanger for exchanging heat betweenfluid flowing in a flow passage in a heat exchanger tube and fluidflowing outside of said heat exchanger tube, wherein a solid bar-likeinsertion member or a hollow bar-like insertion member whose oppositeends are closed is provided in said flow passage in which a fluid havingphase change flows in gas-liquid two phase state or liquid phase state,a cross section of said insertion member is formed into a substantiallycircle shape, a polygonal shape or a starlike shape, and across-sectional area of a flow passage in which said fluid flows isreduced as a mass flow rate quality of said fluid is reduced.
 2. A heatexchanger for exchanging heat between fluid flowing in a flow passage ina heat exchanger tube and fluid flowing outside of said heat exchangertube, wherein a bar-like insertion member is provided in said flowpassage in which a fluid having phase change flows in gas-liquid twophase state or liquid phase state, and a cross-sectional area of a flowpassage in which said fluid flows is reduced as a mass flow rate qualityof said fluid is reduced.
 3. A heat exchanger according to claim 1 or 2, wherein a cross-sectional area of said insertion member isdiscontinuously varied.
 4. A heat exchanger according to claim 1 or 2 ,wherein a cross-sectional area of said insertion member is continuouslyvaried.
 5. A heat exchanger for exchanging heat between fluid flowing ina flow passage in a heat exchanger tube and fluid flowing outside ofsaid heat exchanger tube, wherein a solid bar-like insertion member or ahollow bar-like insertion member whose opposite ends are closed isprovided in said flow passage in which a fluid having phase change flowsin gas-liquid two phase state or liquid phase state, and a cross sectionof said insertion member is formed into a substantially circle shape, apolygonal shape or a starlike shape.
 6. A heat exchanger according toany one of claims 1, 2 and 5, wherein said insertion member is providedon its outer surface with a groove, or a bump and a dip.
 7. A heatexchanger according to any one of claims 1, 2 and 5, wherein saidinsertion member is made of porous material.
 8. A heat exchangeraccording to any one of claims 1, 2 and 5, wherein said insertion memberis provided in plural into bundle.
 9. A heat exchanger according to anyone of claims 1, 2 and 5, wherein a refrigerant comprising hydrofluorocarbon (HFC) or hydrocarbon (HC) as main component is used as saidfluid flowing in said flow passage in said heat exchanger tube.
 10. Aheat exchanger according to claim 3 , wherein said insertion member isprovided on its outer surface with a groove, or a bump and a dip.
 11. Aheat exchanger according to claim 3 , wherein said insertion member ismade of porous material.
 12. A heat exchanger according to claim 3 ,wherein said insertion member is provided in plural into bundle.
 13. Aheat exchanger according to claim 3 , wherein a refrigerant comprisinghydro fluorocarbon (HFC) or hydrocarbon (HC) as main component is usedas said fluid flowing in said flow passage in said heat exchanger tube.14. A heat exchanger according to claim 4 , wherein said insertionmember is provided on its outer surface with a groove, or a bump and adip.
 15. A heat exchanger according to claim 4 , wherein said insertionmember is made of porous material.
 16. A heat exchanger according toclaim 4 , wherein said insertion member is provided in plural intobundle.
 17. A heat exchanger according to claim 4 , wherein arefrigerant comprising hydro fluorocarbon (HFC) or hydrocarbon (HC) asmain component is used as said fluid flowing in said flow passage insaid heat exchanger tube.